If I'd wanted to buy a Houdini Digital Asset for use with any supported plugin or application, I'd be to put it mildly, slightly put off by the general quality of the assets available and the “feel” of the site in general.
I believe asset sharing is a terrific idea and doing it commercially is no bad move either, but then you have to set some standards and implement some sort of lowest common denominator for quality of what is published.
Look at places like http://www.sketchfab.com [sketchfab.com] for example.
A whole different experience that actually makes you want to buy something.
Or go to Turbosquid http://www.turbosquid.com/index.cfm [turbosquid.com] and have a look around. :shock:
These are the places I'd go shopping. But there are no integration with Houdini Assets for these resources.
Now that the Indie versions of both Houdini and the Engine is going good, isn't it time to pay some attention to the asset exchange possibilities? The mentioned sites all integrate via plugins with the same applications that the Houdini Engine is planned for, like 3ds Max and Cinema4D in addition to Maya etc.